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Submission #699716

# Submission time Handle Problem Language Result Execution time Memory
699716 2023-02-17T20:20:52 Z Lobo Parking (CEOI22_parking) C++17
10 / 100
 119 ms 38788 KB 
#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
const int maxn = 4e5+10;

int n, m, b[maxn], t[maxn], in[maxn], done[maxn], out[maxn];
vector<int> pos[maxn], ot[3], g[maxn];

void solve() {
    cin >> n >> m;
    vector<int> ept;
    int cntdone = 0;
    for(int i = 1; i <= m; i++) {
        cin >> b[i] >> t[i];
        
        if(b[i] == 0) {
            ept.pb(i);
            continue;
        }

        if(b[i] != 0) pos[b[i]].pb(i);
        if(t[i] != 0) pos[t[i]].pb(i+m);

        if(b[i] == t[i]) {
            done[b[i]] = 1; cntdone++;
        }
        else if(b[i] != 0 && t[i] != 0) {
            g[t[i]].pb(b[i]);
            out[t[i]]++;
            in[b[i]]++;
        }
    }

    for(int i = 1; i <= n; i++) {
        if(done[i] == 0 && in[i] == 0) {
            ot[out[i]].pb(i);
        }
    }

    vector<pair<int,int>> ans;
    while(true) {
        if(ot[0].size()) {
            int i = ot[0].back(); ot[0].pop_back(); done[i] = 1; cntdone++;
            sort(all(pos[i]));
            int p1 = pos[i][0];
            int p2 = pos[i][1];
            ans.pb(mp(p1,p2));
            b[p1] = 0;
            t[p2] = i;
            ept.pb(p1);
            pos[i][0] = p2+m;
        }
        else if(ot[1].size()) {
            int i = ot[1].back(); ot[1].pop_back(); done[i] = 1; cntdone++;
            sort(all(pos[i]));
            int p1 = pos[i][0];
            int p2 = pos[i][1];
            ans.pb(mp(p2,p1));
            t[p2-m] = 0;
            for(auto x : g[i]) {
                if(--in[x] == 0) {
                    ot[out[x]].pb(x);
                }
            }
            t[p1] = i;
            pos[i][1] = p1+m;
        }
        else if(ot[2].size() && ept.size()) {
            int i = ot[2].back(); ot[2].pop_back(); done[i] = 1; cntdone++;
            int e = ept.back(); ept.pop_back();
            sort(all(pos[i]));
            int p1 = pos[i][0];
            int p2 = pos[i][1];
            ans.pb(mp(p1,e));
            ans.pb(mp(p2,e));
            t[p1-m] = 0;
            t[p2-m] = 0;
            for(auto x : g[i]) {
                if(--in[x] == 0) {
                    ot[out[x]].pb(x);
                }
            }
            b[e] = i;
            t[e] = i;
            pos[i][0] = e;
            pos[i][1] = e+m;
        }
        else if(ept.size() && cntdone != n) {
            for(int j = 1; j <= m; j++) {
                if(b[j] != t[j]) {
                    assert(false);
                    int i = t[j];
                    int e = ept.back(); ept.pop_back();
                    sort(all(pos[i]));
                    ans.pb(mp(j,e));
                    t[j] = 0;
                    b[e] = i;
                    if(pos[i][0] == j+m) pos[i][0] = e;
                    else pos[i][1] = e;
                    if(--in[b[j]] == 0) {
                        ot[out[b[j]]].pb(b[j]);
                    }
                    assert((in[b[j]] == 0 && out[b[j]] == 1));
                    assert(g[i].size() == 1);
                    g[i].clear();
                    out[i] = 0;
                    break;
                }
            }
        }
        else {
            break;
        }
    }

    for(int i = 1; i <= n; i++) {
        if(done[i] == 0) {
            cout << -1 << endl;
            return;
        }
    }
    cout << ans.size() << endl;
    for(auto x : ans) {
        if(x.fr > m) x.fr-= m;
        if(x.sc > m) x.sc-= m;
        cout << x.fr << " " << x.sc << endl;
    }


}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while(tt--) {
        solve();
    }

}

Subtask #1
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 19028 KB Output is correct
2 Correct 10 ms 19072 KB Output is correct
3 Correct 11 ms 19064 KB Output is correct
4 Runtime error 32 ms 38596 KB Execution killed with signal 6
5 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 82 ms 32060 KB Output is correct
2 Correct 119 ms 33688 KB Output is correct
3 Correct 64 ms 29148 KB Output is correct
4 Correct 64 ms 29540 KB Output is correct
5 Correct 113 ms 33164 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 19148 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 19148 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 19188 KB Output is correct
2 Correct 10 ms 19156 KB Output is correct
3 Correct 10 ms 19216 KB Output is correct
4 Runtime error 24 ms 38788 KB Execution killed with signal 6
5 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 19028 KB Output is correct
2 Correct 10 ms 19072 KB Output is correct
3 Correct 11 ms 19064 KB Output is correct
4 Runtime error 32 ms 38596 KB Execution killed with signal 6
5 Halted 0 ms 0 KB -